Omarosa Manigault broke down in tears as she discussed her time in the White House on Celebrity Big Brother, telling a fellow contestant: "It's bad."

The former Apprentice contestant, who was a White House aide until her sudden exit in December, expressed her fears about Donald Trump's presidency in a clip promoting Thursday evening's episode of the hit CBS reality show.

Speaking to fellow contestant, TV personality Ross Mathews, she said she went to the White House because she "felt like it was a call to duty."

"I felt like I was serving my country, not serving him," she said of President Trump.

She whispered to Mathews, "I was haunted by tweets every single day, like what is he gonna tweet next?"

Mathews asked her, "Does anybody say to him, 'What are you doing?'"

Omarosa said that when she tried to be that person, others in the president's inner circle attacked her.

"It was like, 'Keep her away. Don't give her access. Don't let her talk to him,'" she said.

When Mathews asked her, "Should we be worried?" she nodded.

"I'd like to say it's not my problem but I can't say that because, like, it's bad," she said.

Mathews urged her to say it would be OK but Omarosa wouldn't.

"No, it is not gonna be OK," she said. "It's not."

She is in the Celebrity Big Brother house with stars including Keshia Knight Pulliam, Brandi Glanville, Mark McGrath and Chuck Liddell. They are competing for a $250,000 grand prize.

Omarosa left the White House in December amid reports she'd been fired, a claim she and the White House denied. She later said there were things she'd seen in the role that had upset her, and she plans to tell her story.